Answer: The correct answer is C.
Step-by-step explanation:
Mechanical wave is of two types: Longitudinal wave and Transverse wave.
Longitudinal wave is a wave in which the particle motion is parallel to the wave motion. For example, sound wave.
Transverse wave is a wave in which the particle motion is perpendicular to the wave motion. For example, light wave
X-ray: X-ray is an electromagnetic wave. It is a transverse wave.
Red light: It is a light. It is a transverse wave.
Shock wave: Shock wave is a high pressure wave produced by an object. It travels faster than the speed of sound. It is a longitudinal wave.
Radio wave: It is an electromagnetic wave. It is a transverse wave.
Therefore, the shock is longitudinal wave. The correct answer is C.